Method of forming a siftproof package



Sept. 14, 1937. s. D. ANDREW 2,093,067

METHOD OF FORMING A SIFTPROOF PACKAGE Filed Oct. 22, 1956 2 Sheets-Sheet2 q MM n. 113-1, 07 Y :15; m 51 5; B1; :1 g z Jig-12.

6% ATT EY.

Eatented Sept. 14,1937

UNITED STATES METHOD OF FORMING A SIFTPROOF PACKAGE Sumner D. Andrew,Camden, Ark, assignorto Bagpak, Inc., New York, N. Y., a corporation ofDelaware Application October 22, 1936, Serial No. 106,978

2 Claims.

My present invention relates to a method of forming a substantiallysiftproof package which has various advantages over prior art practices.The particular art to which the invention appertains is the art ofutilizing valve bags, su ch bags being formed of one or more plies ofheavy paper and/or fabrics of other types. It is well known in the artthat such bags may permit material to escape through the valve opening,and in order to overcome such tendency it has been customary to form avalve extension as a separate sleeve combined with the bag in itsmanufacture. These sleeves are usually formed of crinkled kraft paperand are usually combined with the bag prior to the formation of the endclosure. So far as I am aware, no practical means have been invented forautomatically combining the sleeve and the bag, the usual practice beingmanually to take each bag from the forming machines subsequent to thefolding of the valve, manually to glue each sleeve into place, and thenmanually to present the bag to a closing unit. Such practice requires anumber of manual steps resulting in a considerable in- 25 crease of costand placing a substantial premium upon sleeve-valve bags. In accordancewith my invention the increase in cost of sleeve-valve bags issubstantially eliminated without increasing the cost of fillingsleeve-valve bags.

30 In accordance with prior practice the greatest utility for suchsleeves was achieved when the sleeve was placed so as to project beyondthe body of the bag, the projecting end requiring skillful manipulationin order that a filling spout 35 could be inserted. In filling anordinaryvalve bag a trained operator can open the valve and insert thefilling spout in one quick motion. However, with a projecting sleeveother motions were required which usually delayed the opera- 40 tor. Inaccordance with my invention the advantages of a projecting sleeve-valvebag are realized without adding materially to the number of operationsto be performed in placing the bag on a filling spout, and entirelyeliminating the 45 operations of combining the sleeve and bag prior tothe filling operation. Other advantages of my invention will be apparentfrom the following description taken in connection with the acocompanying drawings wherein like numerals refer to like partsthroughout.

In the drawings Fig. 1 discloses the first step in the formation of apackage in accordance with my method, the

a view showing the essential idea of placing a bag and illustrating thefact that any type of known in the art, the particular type not beingPATENT OFFICE separate tube or sleeve upon the filling spout prior toplacing the bag thereon;

Fig. 2 discloses a valve bag positioned upon the spout with its valveembracing the previously placed tube and showing material entering the 5bag through the filling spout;

Fig. 3 discloses the filled bag and tube being withdrawn from thefilling spout as a unit:

Fig. 4 discloses a finished package formed as a result of my process,the projecting end of the 10 tube being secured in one of many possiblemanners in order further to prevent the escape of the enclosed contents;

Fig. 5 is a vertical cross-section taken along the line 5-5 of Fig. 2;15

Fig. 6 is a view similar to Fig. 4 showing a package formed with adifferent type of valve valve bag may be utilized in my process; and

Figs. 7-12, inclusive, show various forms of tubes which may be made foruse in my process.

Referring to Figs. 1-5, inclusive, there is disclosed a conventional.filling spout Ill which is an integral part of any valve bag fillingmachine. Material is forced through this filling spout by anyconventional type of means in order to fill the bag. The bag in thepresent instance is of the gusseted, sewn-valve type and comprises sidewalls l2 and gussets I 4. In order to form the valve one of the gussetsis turned outward and then inward to form a reentrant angle at IS, theinner leg of the angle forming the valve l8. A seam 20 closes the end ofthe bag with the exception of the valve opening and a tape 22 may coverthe seam to form a siftproof closure. Other types of closures are wellessential to my invention. In accordance with my invention I form afabricated tube 30, preferably of crinkled kraft paper. The majorrequlrement of this tube is that it should have a diameter such as topermit its being placed upon the filling spout l0. It is, of course,apparent that any valve which can be placed upon the filling spout willlikewise have sufiicient internal diameter to embrace the tube 30 whenin position upon the filling spout. As the material enters the bag itcauses the side walls and the gussets to bulge outwardly, the filled bagtaking substantially the shape of a pillow and causing the reentrantangle at IE to disappear. The material presses upward against the lowerwall of the valve l8 and the weight of the material causes the upperportion of the valve and the top of the bag to rest heavily upon thetube 30.

When the filled bag is withdrawn from the filling spout it is usuallyaccomplished by grasping the bag in the region of the valve and pullingoutwardly. Due to the weight of the material the walls of the bagfrictionally engage the upper half of the tube 30 to a much greaterextent than the tube Ill frictionally engages the which material mightescape. The purpose of the sleeve is to increase the area subjected tothe pressure of the enclosed contents and to plug the slight openingwhich may be left as a result of the still material from which the bagis usually formed.

In order to form a more siftproof closure the projecting end of thesleeve 30 may be turned back and tucked within the valve opening (asillustrated in Fig. 4), or otherwise secured as is well known in theart. It is readily apparent that the expense of forming a package,essentially consisting of a valve bag and its contents and havingsubstantially siftproof characteristics due to the inclusion of a valvesleeve, is materially lessened by my process.

Fig. 6 illustrates the package resulting from the use of my process inconnection with a pasted valve bag formed by folding and adhering theends of the side walls in any manner customary in the art.

Figs. 7-12, inclusive, illustrate various types of fabricated tubeswhich may be used in connection with my invention. Fig. 7 shows a tubeformed by alternately cutting along right and acute angies the productof a tubing unit such as is usually found in a bag forming machine, theweb of paper or other material being longitudinally folded at and ii andadhered at 52. Fig. 8 shows a tube formed by folding a web of paper at53 and joining the adjacent edges by a seam 54. Fig. 9 shows a tubefolded so as to form a diamond-shaped mouth, the tube being created bypasting the overlapped edges of a web of paper at 55. Fig. 10 shows asimple tube formed by folding a web of paper at 56 and joining theadjacent edges by a seam 51, each end of the tube being cut at rightangles to the longitudinal edges. Fig. 11 shows a tube such as would beformed by the tubing unitof atype of bag making machine in whichalternate notches I8 and projecting tabs 59 are formed during thecutting operations which separate an elongated tube formed by folding aweb at fill and I and adhering the edges at 62. Fig. 12 shows a tubeformed on an ordinary tubing unit in which straight-ended sections areseparated from the continuously formed tube, the tube being formed byfolding a web at 83 and 64 and adhering the edges at 65. It is, ofcourse, apparent that various other forms of tubes may be manufacturedin accordance with the type of equipment available, but a feature of thepresent invention is that any type of tube-forming mechanism such as isusually found in a bag making plant may be utilized to fabricatesections of tubes which can be used to carry out my process.

Although I have illustrated various forms which the tube and package mayassume, it should be apparent that there is only one process involved,the process comprising the steps of placing a fabricated tube offlexible. material on the spout of a valve bag filling machine, thenplacing a valve bag on the spout with the valve of the bag embracing thetube, filling the bag in the usual manner and withdrawing the bag andtube as a unit. 'If desired, the tube may be of sufficient length toproject outward from the edge of the bag, and the projecting end thereofmay be secured in order that no material may sift through the tubeitself. The true scope of my invention will be apparent from thefollowing claims.

I claim:

1. The method of forming a substantially siftproof package essentiallyconsisting of a valve bag and its contents, comprising placing afabricated tube of flexible material on the spout of a valve bag fillingmachine, then placing a valve bag on the spout with the valve of the bagemrbracing said tube, filling the bag through said spout, andwithdrawing the filled bag and tube as a unit.

2. The method of forming a substantially siftproof package essentiallyconsisting of a valve bag and its contents, comprising placing afabricated tube of flexible material on the spout of a valve bag fillingmachine, then placing a valve bag on the spout with the valve of the bagem- I bracing most of said tube, filling the bag through said spout,withdrawing the filled bag and tube as a unit, and securing theprojecting end of said tube.

SUMNER. D. ANDREW.

